Tendinopathy is a common clinical disorder. The most common tendinopathy, lateral epicondylitis (tennis elbow) affects up to 3% of the general population. It can be responsible for substantial pain and loss of function of the affected limb for over one year in up to 20% of people. Current management protocols include conservative therapy, e.g., bracing and physiotherapy (66.5% of patients); corticosteroid injections (26% of patients); or surgical resection of the damaged portion of the tendon (7.5% of patients) with patients progressing to the next stage of treatment when their symptoms become too extreme to tolerate. Physicians typically agree that the short-term effects of corticosteroids are outweighed by the longer term consequences of their overuse in this condition. Other common tendinopathies include shoulder (rotator cuff tendinopathy) that affects 1.1% of the population annually, ankle (Achilles tendinopathy), knee (patellar tendinopathy), as well as tendinopathies of the other tendons referenced in Table 1.
Tendinopathy
Tendinopathy is said to be a degenerative condition affecting a tendon. The cause of this degeneration has been thought to be due to one of several causes, of which overuse causing micro-trauma at the tendon enthesis appears to be the most widely accepted. However, practitioners have treated the enthesis as a single unit and have not been cognizant of the biomechanical variation within the enthesis. Instead of targeting an appropriate location within the enthesis in need of treatment, practitioners will treat the entire unit, resulting in inconsistent clinical outcomes. The present invention focuses on the treatment of the osteotendinous junction and not the tendon or musculotendinous junctions.
Histological findings suggest that chronic tendon injuries at the osteotendinous junction are degenerative in nature and not inflammatory. There is an absence of inflammatory cells (e.g., macrophages, neutrophils, monocytes) suggesting that corticosteroid treatment will be of limited benefit in tendinopathy. There is therefore no consensus treatment for tendinopathy (e.g., tennis elbow) within the medical community. As stated previously, this lack of consensus may be because the medical community is viewing the tendon enthesis as a single unit instead of segmenting the regions amenable to treatment. While traditional treatments for tendinopathy have involved the use of corticosteroid injections for pain reduction, it has been shown that corticosteroid injections can further the degeneration of tendons and increase the risk of recurrence of the condition as well as increase the risk of tendon rupture. Nonetheless, corticosteroid injections have been shown to be effective in short term pain reduction for tendinopathy in certain instances. The mechanism is unclear but it is thought that bathing the area with the steroid composition may alter or interfere with the local chemicals that cause the pain stimulus in the area.
Other treatments for tendinopathy include biomechanical reduction of stress on the tendon, relative rest, and ice since it is a vasoconstrictor (and increased vascularity is a finding in tendinopathy) and a natural analgesic. For example, the “RICE” regimen of Rest, Ice, Compression and Elevation is commonly used. Typical conventional treatments also include immobilization of the tendon, such as by the use of a splint or other internal or external structural support, to allow the tendon to heal. In some cases, the only treatment is a long period of rest (e.g., several months) to see if the condition will self-resolve.
Prior art treatments have focused on preserving healthy tendon, rather than treating degenerate tendons (e.g., one or more injections at the musculotendinous junction, where the tendon is not degenerate, to provide structure and support which limits movement and thus protects the healthy tendon). Placing limitations on movement are inconvenient for the patient but, more importantly, these treatments do not resolve the tendon degeneration but merely seek to stop the damage becoming worse. Conventional treatment protocols also suffer from significant disadvantages. For example, the use of corticosteroids can put the patient at risk for tendon rupture and the use of bracing, either internal or external, can have significant lifestyle implications. It would be beneficial if improved methods for treating tendinopathy could be provided.